Railway braking apparatus



May 3,

1.. v. LEWIS RAILWAY BRAKING APPARATUS Filed Dec. 51. 1924 l I I l I I lI l I l l .J

rllll a INVENTOR -%s 4 Air Ja 0p! Patented May 3, 1927.

UNITED STATES PATENT, OFFICE.

LLOYD V. LEWIS, F EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO THE UNIONSWITCH &: SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORIPOTRAILIONOF PENNSYLVANIA.

RAILWAY BRAKING APPARATUS.

Application filed December 31, 1924.. Serial No. (59,205.

My invention relates to railway braking apparatus, and particularly toapparatus of the type comprising trackway mechanism adapted to engagepart of a railway vehicle.

view, partly diagrammatic, showing one form of braking apparatusembodying my invention. 2 is a vertical sectional view along line II-IIof Fig. 1.

Similar reference characters refer to similar parts in both views.

Referring to the drawing, the reference characters 1 and 1 designate thetrack rails of a railway track. These rails are supported, as usual.upon cross ties 2, here shown as steel I-beams. v

Each of these rails is provided with braking apparatus comprising a pairof longitudinally extending members 3 and.4 located on opposite sides ofthe rail. Associated with members 3 and 4 are brake bars 3 and 4,respectively, adapted to engage the opposite faces of a wheel W of arailway vehicle as best illustrated in Fig. 2. Coil springs 5 areinterposed between each brake bar 3" and 4 and the associated members 3and 4 to limit the mechanical pressure of the bar against the wheel tothat which the springs transmit.

Means are provided for moving the brake bars toward and away from theassociated rails. As here shown, this means comprises a plurality ofdrive rods 6 extending transversely 'Wltl]. respect to the track rails,and rigidly attached to each memberB. Associated with each drive rod 6is a second drive rod 7 extending parallel with rod 6 and rigidlyconnected with each member 4'. One end of each rod 6 is provided with atoothed rack 6, and one end of each rod 7 is provided. with a similarrack 7. The rods 6 and 7 are arranged in pairs and the racks 6 and. 7 ofeach pair mesh with a gear 8 pivotally supported by a vertical spindle9. Each such gear is provided with a lever 8. Bearing rollers 10 preventthe racks from springing out of mesh with the associated gear 8. It willbe plain that when the upper end of lever 8 is thrown to the left thecorresponding gear 8 is rotated counter-clockwise so that the associatedrod 6 is moved downwardly and the corresponding rod 7 is moved upwardlyas viewed in Fig. 1. The upper end of each lever 8 is pivotallyvconnected with a longitudinally extending driving link 11, and ittherefore follows that when link 11 is moved to the left, the brake barsfor each rail are moved into the braking position, that is, toward theassociated rail, and when the link 11 is restored to its right-handposition the bars are moved away from the associated rail into theirrelease position. i

The springs 5 are permanently compressed to the desired amount bybolts60 which also serve as a medium forwithdrawing brake bars 3 and 4 whenmembers 3 and 4 are withdrawn from braking positions. p The link 11 isoperated by a fluid pressure motor devicecomprising a cylinder A havinga 'piston14 therein. The piston 14 is connected, by means of a pistonrod 13, anda-link 12 with the extended end of one of the levers 8 andhence with link 11.

The supply of fluid pressure, usually compressed air, to the cylinder Ais con-- trolled by main air valves 27, 30, 33 and35, which main valvesare in turn controlled by three electromagnetic pilot valves R, P and N.Each of these pilot valves comprises a valve. body 18 having a valvedevice 19 therein controlled by a magnet winding 17. The valve 19 isbiased to its upper position by a spring 20 and when in such upperposition connects pipe 22 with atmosphere through port 21. \Vhen magnet17 is energized the valve 19 moves downward against the bias. exerted byspring 20, and pipe 22 is disconnected from atmosphere and connectedwith a source of fluid pressure, not shown in the drawing, through pipe38.

The main air valves are located in a valve body 39. This valve bodycontains a cylinder having a reciprocable piston 24 there in. vThe upperside of this piston is suhjected to the pressure in pipe 22 of valve R.Carried by piston 24 is the main valve 27 biasedto the closed positionby. a coil spring 28. When valve R is tie-energized, then, piston 24 andvalve 27 are int-heir up per positions and port 37 is disconnected fromport and pipe 15 leading to the right-hand side of cylinder A. If, however, valve R is energized, valve 27 is opened so that fluid pressureflows from pipe 38, through port 37, valve 27, port 25, and pipe tocylinder A, thereby driving piston i l to the left and forcing; thebrake bars toward the rails.

The valve body 39 also contains a piston 29 which is controlled by valveP and which in turn controls the main air valve 30 adapted to at timesconnect port with atmosphere through port 31. hen valve 1 isClo-energized, and valve 2? is closed, pisten 29 and valve 30 move intotheir lower positions under the influence of gravity. lVhen valve P .isenergized, the upper side of piston 29 is exposed to the pressure frompipe 22. Since the area of piston 29 1S greater than that of valve 30.the valve 30 will be moved downwardly even if valve 27 is open, andcommunication between ports 25 and 31 will thus be interrupted.

In similar manner valve N controls the pressure applied to the upperside of a piston 32 reciprocable in valve body 3.) and controlling thetwo main air valves 33 and 35. A spring; 36 biases the piston and thevalves controlled thereby to their upper positions. in which pipe 16,leading to the lett-hand end of cylinder A, is connected with atmosphere through port l0, valve 33 and port 34. lVhen valve N is energizedpressure from pipe 22 forces piston 32 downward, closing valve 33 andopening valve 35, thus supplying fluid pressure to thele'ft-hand side ofcylinder A through port 37, valve 35. port 40, and pipe 16. It should benoticed that due to the size of the piston rod 13. the area over whichthis pressure is effective upon piston 1d is comparatively small. Theforce exerted upon the piston and the brake mechanism to withdraw thebraking bars from the braking position is therefore coluparativelysmall. The purpose of this feature is to avoid the waste of connin'essedair energy that would result were the piston rod not thus enlarged and anearly equal piston area used for both brake application and release.

Under certain conditions it is desirable to operate braking apparatus ofthe type here described, from a point remote from the. apparatus. as inthe case where a number of sets of apparatus are to be controlled from asingle station. it the control valve be located at the control stationand the pipes 15 and 16 run to the traclrway apparatus, the excessivequantity of air required would make the expense of this purely pneumaticcontrol almost prohibitive; furthermore, the inertia of tlie largeamount of air in pipe lines. etc.. would make the functionint; of theapparatus sluggish and uncertain. and condensation from the large airvolume entailed would result in unreliability of operation.

.l there'lore preter to locate the control valves adjacent the cylinderA, and to control these valves electrically from a remote point, such asa control cabin H. For this purpose I provide two manually operablecontact levers 41:5 and 47, located at the point H from which it isdesired to control the braking apparatus. Lever 15 is adapted to bemoved into engagement with a fixed con tact 46 to supply energy towinding; 17 of valve P from a suitable source. such as a battery 50.Associated with lever 4-7 are a plurality of fixed contacts 48, 55. 5(3,5?, 58 and 59, so disposed that lever t? may make contact with anyselected one of the fixed contacts or with none 011' them. When contactl-T4.S is closed, winding: 1'? of valve N is energized by current frombattery 51). as will be obvious from the drawing.

Communieating;- with the right-hand end of cylinder A is a pressurelGSPUl'ISlVQ device 53 having a diaphragm 52 exposed to the pressure inthe cylinder. A pivoted lever 51 is operatively connected with the dia-)lll'ilgll'l so that when the air in the right hand side of cylinder Aisat atmospheric pressure. lever 51 makes contact with a. plurality ofcontact sectors 55, 56. 57, 58. 59 which sectors are connectedelectrically with contacts 55, 56 57, 58 and 5!), respectively, throughwires 55* 56", 57", 58" and 59*. If, however, the pressure in therighthand side of cylinder A is increased, diaphragm 52 swings lever 51toward the right to successively disengage the contact segments, contact55-51 being first broken. It follows, therefore, that for any of the contacts controlled by diaphragm 52, there is a maximum pressure incylinder A, and it this pressure be exceeded, such contact will heopened. Although I have here illustrated only live contacts controlledby lever 51, it should be understood that this particular number is notessential. Lover 51 is connected with one terminal of winding 17 ofvalve R. and battery has one terminal connected with lever 45? and theother terminal connected" with the ren'iaining terminal of winding 17 ofvalve 1%.

ln explainingthe operation of the apparatus, I will assume that arailway vehicle is moving along the track shown in the drawing, andthat. the braking apparatus is in the illustrated pm'iition, that is.all the manually operable contacts at point [-1 are open, valves R, land N are all deenergized, the braking apparatus is in the releaseposition. and pressure is disconnected from both sides of cylinder A.

I will also assume that the operator at H wishes to make a light brakeapplication. He first closes contact 45l6, energizing valve P andclosing valve 80. He then closes contact l755. Valve R then becomesenergized over a circuit including contact 51 and valve 27 is thereforeopened to gradually apply fluid pressure to the right-hand end ofcylinder A. This pressure drives pistonl l to the left and moves thebrake bars 3 and 4* into position for engagement with the wheels of thevehicle; The pressure thus supplied to cylinder A is applied also todiaphragm 52 and after reaching a predetermined value causes contact51--55 to open. The circuit forvalve Itis then interrupted, and valve 27closes, preventing further increase in the braking force. Should theoperator wish to increase the amount of the brake application he can doso by moving lever-4r7 into engagement with a lower contact, such as 58,thereby again closingthe circuit for valve R, this time through contact5158 and valve R will be energized to open 27. The pressure supplied tocylinder A will then be increased till contact 51.58 opens, where-Should the operator desire to reduce the, braking pressure he firstmoves contact arm 47 to a lower pressure contact position, and thenopens contact4546, thereby deenergizing valve P and allowing a portionof the fluid in the cylinder A to vent to atmosphere through valve 30.This reduction in pressure may be stopped at any time by reclosingcontact 45-46.

It is plain from the foregoing that with my invention. an operatorlocated at a point remote from the braking apparatus may control thebraking pressure accurately and instantaneously.

Should the operator wish to restore the apparatus to the releaseposition, he opens contact 45-4l6 and all the contacts controlled. bylever 47, reducing the pressure in the right-hand side of cylinder A toatmospheric pressure He then closes contact 47-48. The resultingenergization of valve N opens valve 35 to supply fluid pressure to theleft-hand end of cylinder A, thereby driving piston 14 to the right andrestoring the braking apparatus to the release position. The subsequentopening of contact 4748 de energizes valve N, opens valve 33, and valve35 being closed, vents the lefthand side of cylinder A to atmosphere torestore the apparatus to its normal condition.

In this application I do not make any claim for the invention describedand claimed in an application filed on even date herewith, Serial No.759,209, by John P. Coleman, for railway braking apparatus.

, Although I have herein shown and described only one form of brakingapparatus embodying my invention, it is understood that various changesandmodifications may be made therein within the scope of the appendedclaims without departing from the spirit'and scope otmy invention.

Having thus described my invention, what I claim is: i i

1. Railway braking apparatus comprising a brake bar'located in thetrackway,a fluid pressure motor for operating said bar, a plurality ofcontacts successively actuated as the pressure supplied to said motorincreases, and means including said contacts for supplying fluidpressure to saidmotor.

2. Railway braking apparatus comprising a brake bar located in thetrackway, a motor for operating said bar,a plurality of contactssuccessively. actuated as the energy supplied to said motor increases,and means including said contacts for supplying en ergy to said motor.

Railway braking apparatus comprising a brake bar located in thetrackway, a motor for operating said bar, a plurality of normally closedcontacts successively opened as the energy supplied to said motorincreases, a winding for controlling the supply of en ergy to saidmotor, and manually operable means locatedat a point remote from saidmotor for supplyingcurrent to said winding A in series with any selectedone of said con tacts. I i

4. Railwaybraking apparatus comprising a brake bar located in thetrackway, a fluid pressure motor for moving said bar into engagementwith apart of a railway vehicle, means for supplying fluid pressure tosaid motor, pressure limiting means responsive to the actual pressure ofthe fluid in the motor and effective when actuated to discontinue suchsupply, and manually operable means for selecting the pressure at whichsaid pressure limiting means will be actuated.

5. Railway braking aprmratus comprising a brake bar located in thetrackway, a cylinder, a piston in said cylinder operatively connectedwith said bar, a device responsive to the pressure supplied to saidcylinder, manually operable means, a first valve controlled by saiddevice and by said manually operable means for admitting fluid pressureto said cylinder, and a second valve controlled solely by said manuallyoperable means for releasing pressure from said cylinder.

6. Railway braking apparatus comprising abrake bar located in thetrackway, a cylinder, a piston in said cylinder operatively connectedwith said bar, means for initiating the supply of fluid pressure to saidcylinder, and means responsive to the pressure supplied to said cylinderfor discontinuing v such supply.

7. Railway braking apparatus comprising a brake bar located in thetrackway, a cylinder, a piston in said cylinder operatively connectedwith said bar, means for initiating the supply of fluid pressure to saidcylinder, and means responsive to the pressure in said :ylinder fordiscontinuing such supply when the pressure in the cylinder reaches apredetermined value.

8. Railway braking apparatus comprising a brake bar located in thetrackway, a cylinder, a piston in said cylinder operatively connectedwith said bar, a device responsive to the pressure in said cylinder, aplurality r of normally closed contacts controlled by said device andarranged to he successively opened as the pressure in the cylinderincreases, and means including said contacts for supplying fluidpressure to saidcylinder.

9. Railway braking apparatus comprising a brake bar located in thetrackway, a cylinder, a piston in said cylinder operatively connectedwith said bar, a device responsive to the pressure in said cylinder, aplurality of normally closed contacts controlled by said device andarranged to be successively opened as the pressure in the cylinderincreases, an electro magnetic valve for supplying fluid pressure tosaid cylinder, and manually operable means located at a point remotefrom said cylinder for at times supplying current to said valve inseries with any one of said contacts.

10. Railway braking apparatus comprising a brake bar located in thetrackway, a

one of said normally closed contacts, manual means for closing any oneof said normally open contacts, a winding for controlling the supply ofenergy to said motor, and a circuit "for said winding includingwhichever of said normally open contacts may be closed and theassociated normally closed contact.

11. Railway braking apparatus comprising a brake bar located in thetrackway, a cylinder, a piston in said cylinder operatively connectedwith said bar, a device responsive to the pressure in said cylinder, aplurality of normally closed contacts controlled by said device andarranged to be successively opened as the pressure in the cylinderincreases, a plurality of normally open contacts located at a pointremote from raid cylinder and each electrically connectcd with one ofsaid normally closed contacts, manual means for closing any selected oneof said normally open contacts, an electropneumatic valve for supplyingfluid pressure to said cylinder, and a circuit for said Valve includingwhichever of said normally open contacts may be closed and theassociated normally closed contact.

In testimony whereof I aflix my signature.

LLOYD v. LEWIS.

